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Joel Ullom (Fed)

Dr. Joel Ullom leads the NIST Quantum Sensors Division. He is also a Lecturer in the Department of Physics at the University of Colorado Boulder. Dr. Ullom has worked in the fields of low temperature sensors, quantum electronics, and cryogenic systems since 1994. During this time, he has done research to understand and improve the performance of superconducting transition-edge sensors. He has also worked to develop different types of refrigerators including microcoolers based on quantum tunneling and macrocoolers that reduce the need for liquid cryogens. Dr. Ullom has developed and disseminated a variety of instruments based on multiplexed arrays of cryogenic sensors.

Research Interests

  • cryogenic sensors
  • multiplexed readout techniques
  • advanced cryogenics
  • radiation detection
  • applications of cryogenic sensors in materials analysis, astrophysics, cosmology, fundamental parameters, and quantum information science

Awards

Publications

280-GHz aluminum MKID arrays for the Fred Young Submillimeter Telescope

Author(s)
Anna Vaskuri, Jordan Wheeler, Jason Austermann, Michael Vissers, James Beall, James R. Burgoyne, Victoria Butler, Scott Chapman, Steve K. Choi, Abigail Crites, Cody J. Duell, Rodrigo Freundt, Anthony Huber, Zachary Huber, Johannes Hubmayr, Jozsef Imrek, Ben Keller, Lawrence Lin, Alicia Middleton, Michael D. Niemack, Thomas Nikola, Douglas Scott, Adrian Sinclair, Ema Smith, Gordon Stacey, Joel Ullom, Jeffrey Van Lanen, Eve Vavagiakis, Samantha Walker, Bugao Zou
First light observations of the 280 GHz instrument module of the Fred Young Submillimeter Telescope (FYST) in the CCAT Collaboration are expected in 2026. The

Application of hard x-ray and gamma-ray TES microcalorimeters at an accelerator facility

Author(s)
Takeshi Saito, Shinji Okada, Yuichi Toyoma, Toshiyuki Azuma, Gonçalo Baptista, Daniel Becker, Douglas Bennett, William Doriese, Joseph Fowler, Johnathon Gard, Tadashi Hashimoto, Ryota Hayakawa, Tasuku HAYASHI, Yuto Ichinohe, Josef Imrek, Paul Indelicato, Tadaaki Isobe, Sohtaro Kanda, Naritoshi Kawamura, John Mates, Yasuhiro Miyake, Kelsey Morgan, Hirofumi Noda, Galen O'Neil, Takuma Okumura, Nancy Paul, Daniel Schmidt, Kouichiro Shimomura, Patrick Strasser, Daniel Swetz, Tadayuki Takahashi, Motonobu Tampo, Joel Ullom, Izumi Umegaki, Joel Weber, Shinya Yamada, Daikang Yan
The x-ray spectroscopy of the muonic atom has attracted atomic, nuclear, and particle physicists since its discovery. The properties of a muonic atom, such as

Towards Precision Spectroscopy of Antiprotonic Atoms for Probing Strong-field QED

Author(s)
Gonçalo Baptista, Shikha Rathi, Michael Roosa, Quentin Senetaire, Jonas Sommerfeldt, Toshiyuki Azuma, Daniel Becker, Francois Butin, Ofir Eizenberg, Joseph Fowler, Hiroyuki Fujioka, Davide Gamba, Nabil Garroum, Mauro Guerra, Tadashi Hashimoto, Takashi Higuchi, Paul Indelicato, Jorge Machado, Kelsey Morgan, Francois Nez, Jason Nobles, Ben Ohayon, Shinji Okada, Daniel Schmidt, Daniel Swetz, Joel Ullom, Pauline Yzombard, Marco Zito, Nancy Paul
PAX (antiProtonic Atom X-ray spectroscopy) is a new experiment with the aim to test strong-field quantum electrodynamics (QED) effects by performing high

Patents (2018-Present)

Compact Low-power Cryo-Cooling Systems For Superconducting Elements

NIST Inventors
Joel Ullom and Vincent Kotsubo
A compact, low power cryo-cooler for cryogenic systems capable of cooling gas to at least as low as 2.5 K. The cryo-cooler has a room temperature compressor followed by filtration. Within the cryostat, four counterflow heat exchangers precool the incoming high-pressure gas using the outflowing low
X-Ray Spectrometer

X-Ray Spectrometer

NIST Inventors
Kevin L. Silverman , Carl D. Reintsema , Galen O'Neil , Luis Miaja Avila , Daniel Swetz , W.Bertrand (Randy) Doriese , Dan Schmidt , Bradley Alpert , Joseph Fowler , Joel Ullom and Ralph Jimenez
This invention includes: an x-ray plasma source that produces primary x-rays; an x-ray optic that transmits and focuses the primary x-ray onto a sample jet from which fluorescence x-ray are emitted; and a microcalorimeter array detector that measures the energy of the incoming fluorescence x-rays
Created October 9, 2019, Updated October 23, 2023
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